ZXR750 rebuild #3

[JimZXR]

As the title suggests I'm now onto my third ZXR750 (love these bikes), this time I bought from a forum member (former member now possibly) to keep it in the family so to speak!

Bit of a strange bike though as its a 1992 L1 model but I thought the L1 was only available from 1993! Another strange fact is that it has a J model motor! Not sure if its been put in after a blow up or was factory fitted but either way I'm good as I have an L motor to get donor cams from!

The bike came with plenty of upgrades already done or the parts there to do them like ZX7R front end, ZX7R shock, spare sprockets of varying size, adjustable rear sets (not fitted), braided lines all round, tinted screen, QA throttle with spare tubes and a front radial MC!

Starting to tear it down now, fairings and tank are off, electrics seem fine but a few issues, fuel tank is fucked internally by the sounds of it! Guy said it was rusty but the cap lock has seized up so no chance of opening it yet!

Tried to start it but no joy, lights dip a little when I hit the button but the starter doesn't turn! Have turned the motor over by hand and all seems good so gonna check the solenoid first then move through the system.

Hopefully this bike will finally get me back on the road since the track bike was awesome on the track this should make a good road bike!

Started a paint thread below but will probably keep the rebuild details on this page.
http://www.ksrc-au.com/phpBB3/viewtopic ... 46&t=43546

[Kwak addict]

I made Tom an offer on this but you beat me to it (which is probly not a bad thing seeing as I already have 3 ZXR 7/9s )
I owned it many years ago & sold it to a mate who sold it to Tom who sold it to you - it's getting to be a bit of a whore now
I'll be following this build with interest, good luck with it.

[JimZXR]

Any idea where the J model engine came from?

[JimZXR]

Got it to turn the starter motor tonight but having issues with both my fuel tanks so lending one off a member over the weekend so will hopefully get it to fire!
Put a new lithium battery into it too so plenty of juice for cranking it now!
Update again soon.....

[Kwak addict]

Any idea where the J model engine came from?

Nope, news to me.
How do you tell if it's a J or L motor? the engine number?

[JimZXR]

Yeah, the engine number, like the frame numbers, have a letter that illustrates the model number.

The frame is an L1 but the motor is a J model!

Go it to fire oniony but only hey hard starting it (fuel down cylinder) so at least I know the issue now is the carbs as the float bowls were full of fuel from when I'd tried to start it normally.

Carbs are now off and awaiting stripping.

Hopefully it'll be a quick fix then I can get the electrics sorted and be off for a Blue slip!

[willrcr15]

Hey Jim,
I understand, it's like a need for drugs, you just can't be without it.
I've got leftover carbies, 3 stamped 89 probably off a 90 model & 1 stamped 94, all complete & in perfect cond, if you need any parts.
A mate picked up a 2000 zx7r in great nick for $1400 it's got a few fixable maintenance issues but still a cheap buy, can't wait to have a ride.
I put a Factory Pro kit in mine, adjustable Titanium needles & new mains & what a difference, it has tidied up the accelaration & she pulls better from lower revs but best of all it blasts up into the red line like a snap of the fingers, sorry dribbling again, So I have needles & std jets left over if you need parts.
I've got my own ideas on the paint scheme but its good to see what others have done, as soon as the weather warms up I'll finish her & post some pics.
By the way, I asked the locals at Broadmeadow for some No. 40 pilot jets but they can't help, does anyone know where they can be bought ?
Regards

[Jason]

Guy said it was rusty but the cap lock has seized up so no chance of opening it yet!

I had the same problem with the tank lock on my 1991 ZXR750 which had suffered a couple of years unplanned storage/lack of use.

I tried everything I could think of to loosen the lock.... turning the tank upside & soaking in fuel/tapping various locations on the cap assembly/spraying with freeze spray/soaking in copious amounts of WD40 (I knew you weren't suppposed to put liquid lubricant on locks, but it was desperate times).... didn't want to push it so far as to break the key though.... in the end I found a solution that worked for me, and that was very gently heat soaking the cap assembly with an electric heat gun... after about 10 minutes, the key turned quite easily & I was able to unlatch the lock.

It turned out that it was a green paste like substance that had gummed up the latch, I guess something from the dodgey fuel that had deteriorated over the time in storage.

I'd say of course that anyone trying this heat gun method should obviously drain all the fuel, & vent it out with an inert gas... I didn't use an inert gas, but the tank had been dry for a long time beforehand.

Jason

[dutchy]

It turned out that it was a green paste like substance that had gummed up the latch, I guess something from the dodgey fuel that had deteriorated over the time in storage.

............or the latch was simply seized by the usual rust or corrosion from being stored/unused, and the gunk came as a result of all the crap that was sprayed/used/inserted/heated trying to open it again

[JimZXR]

Just been advised by the previous owner that the bike always started fine so I'm hopeful that the carbs merely need a clean out and a blow through.
Will hopefully have a bit if time this weekend to get them stripped, cleaned, refitted then a test fire!

[JimZXR]

So, got it o start today by filling the float bowls manually after I'd rebuilt the carbs. Bit smokey but think it'll pass with some fuel system cleaner though it.

Bad thing is that once I'd refitted the airbox and fuel tank and hooked up the fuel lines it's no longer running! From that I think I've a problem with either the fuel pump; squashed fuel lines; electrical supply to pump or all!

Am confident it can be fixed and will keep positing until it is but for today I'm claiming a victory!

[JimZXR]

So, after wracking my brains earlier (which are limited due to me fighting off the flu) I decided to have another crack at the bike to investigate the fuel starvation; turns out it has had a fuel line replacement at some time using plain fuel line, which is fine but it doesn't want to go round the 90 degree bends like the formed ones do thus causing fuel starvation!

A bit I a jiggle and all good but think I'll replace it with the OEM one next week!

But of a rattle in the motor when it starte this time but it cleared quickly. It warms up well and the fan cuts in just right. Electrics are good except I can't yet find the horn or front brake connections.

Once the electric niggles and fuel line are sorted ill give it a good service, a really good wash then start attacking the chain to clean it up before getting the fairings back on and sort out and fitment issues before Blue slip!

Phew; not much then!

Oh; and all hopefully before baby's arrival in 2 weeks!

[JimZXR]

Ordered fuel line yesterday, collect on Friday.

Picked up and fitted new horn last night only to find it sounds like it should be on a Vespa! Sounds like the road runner!

Spoke to BikeBiz and they've got the missing fairing bracket off the V-piece in stock; RESULT!

[JimZXR]

Picked up V-piece bracket yesterday and hope to get some time on it next week.

Am already considering the options as I'll have to graft two recessed mounting points onto the lower fairings then drill it to suit. Plenty of work but hopefully all will work out.

Am open to advice or guidance if anyone can assist?

[JimZXR]

Gotta love it when fibreglass fairings are a little out!

It's either that or the headlight bracket is slightly off which means a quick swap over but luckily I have a few spares!

Received my Kaneg spools yesterday so after machining a little extra collar they'll be fitted then I can move my attention to the front end and get the forks off to Glenn at Allfixed (thanks or the recommendation all).

Have a few wiring issues to sort:
fit the fairings again;
fix the intermittent starting issue;
Clean up the chain and sprockets;
clean up or swap the wheels;
Check all the lights;
Fit the fairing brackets and mirrors;
Test ride;
BLUE SLIP!

Last time I buy a bike that isn't ready to go.....

honest!!!

A Crim next I think! Or go completely the other way and break the above statement and do a cafe build!